Rotary rivet dispenser

ABSTRACT

A rotary rivet dispenser for feeding slug rivets to an injector mechanism on the head of an automatic riveting machine. A rotary rivet slug container with an inner scoop aligns rivet slugs in the container for movement into a delivery tube by gravity feed assisted by intermittent air pressure.

United States Patent Earl K. Kelly Lynwood, Calif.

June 1, 1970 Jan. 11, 1972 McDonnell Douglas Corporation inventor Appl.N 0. Filed Patented Assignee ROTARY RIVET DISPENSER 3 Claims, 2 DrawingFigs.

us. c1 221/167,

I 221/182 1111. c1. B65g 47/14 Field of Search 221/173,

[5 6] References Cited UNITED STATES PATENTS 2,678,238 5/1954 Schutz222/167 X 1,221,136 4/1917 Boudwin 222/167 1,146,024 7/1915 Rumney221/182 X 1,741,033 12/1929 Neidlinger.. 221/182 3,101,832 8/1963 Wyle221/173 X 1,481,064 1/1924 Ochs 221/177 X Primary Examiner- Robert- B.Reeves Assistant Examiner-Thomas E. Kocovsky Attorneyx-Walter .1. Jason,Donald L. Royer and Robert 0.

Richardson ABSTRACT: A rotary rivet dispenser for feeding slug rivets toan injector mechanism on the head of an automatic riveting machine. Arotary rivet slug container with an inner scoop aligns rivet slugs inthe container for movement into a delivery tube by gravity feed assistedby intermittent air pressure.

ROTARY RIVET DISPENSER cl BACKGROUND OF THE PRESENT INVENTION Rivethoppers usually furnished with riveting machines typically utilize areciprocating blade to align each rivet slug for delivery through a tubeby gravity feed. The hoppers occasionally cut or otherwise damage rivetslugs but unless the hopper feed jams, the damage is not detected. Onone occasion, the inspection of riveted panels revealed an average of i5damaged rivets per panel and these rivets had to be removed andreplaced. This required hand labor, requiring an average of 3 minutesper rivet. Moreover, defective rivets that were not easily detectedremained in the finished panel to give the panel a latent structuralweakness. These hoppers were found to jam on an average of four or fivetimes per 8-hour shift. These required the operator to climb to theexterior surface of the panel to reach the hopper and clear theobstruction. Usually, the damage to the hopper mechanism results inminutes downtime while the maintenance mechanic installs a replacementhopper. In addition, during the operation noted, the maintenance machineshop expended an average of 74 hours per month making replacement partsand repairing damaged hoppers.

A vibratory bowl feeder has been used as a replacement for deliveringthese rivet slugs, and while they are moderately successful, they alsoare bulky, complex and costly.

SUMMARY OF THE PRESENT INVENTION The rotary rivet dispenser comprisingthe present invention includes a cone which rotates within a bearinghousing and a detachable rivet container cup secured to the base openingof the cone. A rivet pickup tube having a scoop is fixed inside the conecavity against an inner surface wall. The apex of the cone is normallyheld below the horizontal tilt axis for gravity feed of the rivets intoa delivery tube. With each revolution of the cone and container cupassembly, the scoop gathers and aligns rivet slugs which travel down thetube by gravity feed, assisted by intermittent air pressure. A singlehole is drilled radially through the cone. This hole passes under theend of an air pipe which directs a continuous stream in close proximityto the surface of the cone to provide an airblast through the hole witheach revolution.

The advantages of the rotary rivet dispenser are compactness, mechanicalsimplicity, reliable operation, and elimination of damage to rivetslugs. Time loss and added production costs incurred by removal andreplacement of defective rivets and the possibilty of undetectedriveting faults in finished products are also eliminated. Installationof the dispenser on existing riveting machines is simple, since the newdispenser utilizes the same mount as the old hoppers. Absence of movingparts within the cone and container cup eliminates the possibility ofdamage to rivet slugs. Application of a simple and reliable rotarymotion is characterized by smoother action of less complexity thanreciprocating or oscillating devices. The design of the jamproofdelivery path and pickup scoop allows excess slugs to merely spill outof the scoop when the delivery tube is filled to capacity. The abilityto discard or reject excess slugs without loss, damage or malfunction isa major advantage of this dispenser. Another advantage is that thisdispenser is self-cleaning when it is desirable to change sizes ofrivets.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is an exploded view inperspective of the rotary rivet dispenser; and

FIG. 2 is a plan sectional view illustrating its operation.

Reference is now made to FIG. 1. Here there is shown a mounting plate 10adapted to be mounted on an automatic riveting machine, not shown. Thismounting plate has an opening 12 therein, through which a delivery tube14 is extended and attached thereto by collar 16. This delivery tubecarries rivet slugs, 18 in FIG. 2, with a gravity feed to apredetermined position within the automatic riveting machine, not shown.This delivery tube 14 is flared at its upper end 20 to facilitatealignment of end 22 of rivet pickup tube 24 when the pickup tube ispositioned for use.

Mounting plate 10 has a pair of support arms 26 at the end of which is abearing housing 28 pivotally mounted by bushing pins 30. A locking screwcrank 32 extends through one of the support arms 26 and into an aperturein bearing housing 28 to establish the tilt axis of cone housing 34 andto align end 22 of tube 24 with end 20 of delivery tube I4. Bearinghousing 28 has an inner shoulder 36 against which is positioned theouter race 38 of a ball bearing assembly 40. This assembly includes theinner race 42, bearings 44 and the outer race 38. An annular dust cover46 fastened to the outer surface of the bearing housing 28 retains theball bearing assembly 40 in position. The cavitated cone housing 34 ispositioned within the inner race 42 which retains the housing 34 as itrotates. An electric motor 48 is positioned on a motor mount 50 fastenedto the bearing housing 28. An O-ring belt 52 passes over the motorpulley 54 and around an annular groove 56 in the cone housing 34 tocause rotation thereof.

Rivet pickup tube 24 extends from its end 22, shown aligned with end 20of delivery tube 14, through the apex 58 of the cone housing 34 andthrough a baffle plate 60 which forms the base of the dispenser. Thetube 24 is bent out of alignment with the axis of the cone, about whichaxis the cone and tube rotates, so that its inner end contacts the innerwall 62 of the cone housing 34. This inner end of tube 24 is split andbent open to form a cradle 64, slot 66 and scoop 68. The leading edge ofthe scoop 68 faces the direction of rotation of the cone shown by arrow70. The scoop 68 engages the inner wall surface 62 and on the downsideof its rotation scoops up a plurality of rivets through the slot 66between the scoop 68 and cradle 64. The slugs rest in alignment onthecradle 64 as the scoop 68 approaches the top or high point of itscircle of revolution. Since the axis of rotation is not horizontal buttilts downward along the axis of delivery tube 14 and end 22 of pickuptube 24, all slugs in the dispensing cone will find their way throughthe slot 66 and down the tube 24.

Cradle 64 has an arcuate cutout portion 72 adjacent its intersectionwith baffle plate 60 to prevent jamming by enabling a rivet slug notproperly oriented and aligned with the tube opening to simply fall outand drop back into the pile of slugs in the dispenser again.

An airblast tube 74 is affixed to one of the support arms 26 andprovides an airstream against the outer surface of cone housing 34. Anopening 76 in the housing is aligned to receive and pass the airblastinto the housing when the scoop 68 is at the top. This momentarilypressurizes the housing and pushes a slug on cradle 64 into the pickuptube 24. The cradled slugs are shielded from the direct airblast by thecradle 64.

A detachable rivet container cup 78 completes the dispenser assembly. Ithas an annular groove 80 around the outer surface near the open endthereof so that it may be secured to the cavitated cone housing 34.Brackets 82 mounted on cone housing 34 have spring-loaded balls 84therein which releasably engage groove 80 in the rivet container cup 78.The rivet container cup thus may be quickly disengaged and refilled whenthe rivets placed therein have become exhausted.

When refilling the container cup 78, crank 32 is first turned from itslocking position and the entire assembly (housing 34, tube 24 and cup78) is tilted to a vertical position with the cup 78 extended downward.The housing is thus self-cleaning and all remaining slugs are in the cup78 for easy removal. Slugs of another size may then be used, as desired,by simply snapping in another cup with slugs of the desired size. Theassembly is then pivoted back into position and locked by crank 32.

Reference is now made to FIG. 2. Here there is shown a plurality ofrivet slugs 18 randomly oriented within the cone housing 34 and, becauseof the incline, resting against the inner surface wall 62. Scoop 68 withthe slot 66 facing the direction of rotation shown by arrow 70 ispositioned against the inner wall surface 62. Cradle 64 of scoop 68 hasa slug 86 therein when in its top position of rotation. Opening 76 inhousing 34 is aligned with air pipe 74 when the scoop 68 is at the top.As opening 76 becomes aligned with the air pipe 74, a blast of air 88 isinjected into the container to assist in the movement of the rivet slugsthrough the rivet pickup tube 24 and down into the delivery tube 14, notshown.

Having thus described one form of my invention, it is to be understoodthat modifications thereof will readily occur to those skilled in theart and that these improvements are also to be considered as part of thepresent invention as defined by the claims herein.

lclaim:

l. A rotary dispenser of cylindrical objects comprising:

a housing,

means for rotating said housing,

a pickup tube within said housing and terminating at one end in a scopehaving a cradle thereon,

said scoop being positioned against an inner wall of said housing forreceiving said objects in the cradle thereof as said housing is rotated,

said housing having a baseplate through which said pickup tube extends,said cradle having an arcuate cutout therein adjacent said baseplatewhereby objects misaligned in said scoop and cradle fall out as saidhousing is rotated, said housing being rotatable about a nonhorizontalaxis,

said housing being rotatably and pivotally mounted on support arms on amounting frame having an end of a delivery tube affixed thereto,

said pickup tube having a lower end extending from said housing andalong the rotational axis thereof,

said pickup tube lower end being in alignment with said delivery tubeupper end to pass said objects therethrough, said housing having anaperture therein,

means projecting an airstream through said aperture upon each revolutionof said housing,

said scoop being at its uppermost position during its rotation when saidairstream passes through said aperture to pressurize said housing andthereby propel objects on said cradle into said pickup tube.

2. A rotary dispenser as in claim 1 wherein said housing is alsopivotally mounted on said mounting frame and wherein said housing may bepivoted to a vertical position with said pickup tube lower end extendingupward,

an object container cup detachably affixed to said housing to supplysaid housing with objects to be passed through said pickup tube, and

wherein a lock crank releasably retains said housing in pivotal positionwherein said pickup tube and said delivery tube are aligned.

3. A rotary dispenser as in claim 2 wherein said housing hasspring-pressed detent means thereon, and said cup has an annular groovethereon, said detent means engaging said groove when said container cupis positioned on said housing.

1. A rotary dispenser of cylindrical objects comprising: a housing,means for rotating said housing, a pickup tube within said housing andterminating at one end in a scope having a cradle thereon, said scoopbeing positioned against an inner wall of said housing for receivingsaid objects in the cradle thereof as said housing is rotated, saidhousing having a baseplate through which said pickup tube extends, saidcradle having an arcuate cutout therein adjacent said baseplate wherebyobjects misaligned in said scoop and cradle fall out as said housing isrotated, said housing being rotatable about a nonhorizontal axis, saidhousing being rotatably and pivotally mounted on support arms on amounting frame having an end of a delivery tube affixed thereto, saidpickup tube having a lower end extending from said housing and along therotational axis thereof, said pickup tube lower end being in alignmentwith said delivery tube upper end to pass said objects therethrough,said housing having an aperture therein, means projecting an airstreamthrough said aperture upon each revolution of said housing, said scoopbeing at its uppermost position during its rotation when said airstreampasses through said aperture to pressurize said housing and therebypropel objects on said cradle into said pickup tube.
 2. A rotarydispenser as in claim 1 wherein said housing is also pivotally mountedon said mounting frame and wherein said housing may be pivoted to avertical position with said pickup tube lower end extending upward, anobject container cup detachably affixed to said housing to supply saidhousing with objects to be passed through said pickup tube, and whereina lock crank releasably retains said housing in pivotal position whereinsaid pickup tube and said delivery tube are aligned.
 3. A rotarydispenser as in claim 2 wherein said housing has spring-pressed detentmeans thereon, and said cup has an annular groove thereon, said detentmeans engaging said groove when said container cuP is positioned on saidhousing.